I purchased a 2016 Chevy Trax LT in October 2020. I've been impressed with the car as this is my first subcompact. I recently took it in for service at the dealership and asked them to look into a rubbing noise I was hearing when I turned in either direction. Service said it was due to rust build up on the rotors. Is this normal? How can I get rid of the rust? Any help is greatly appreciated!